EFFECTIVE 3D REGULARIZED XFEM FOR PULL-OUT OF STEEL BARS IN CONCRETE, BENDING AND SHEAR TESTS ON FRP-REINFORCED CONCRETE BEAMS

Fibre-reinforced polymer (FRP)-reinforced concrete members exhibit low ductility due to the linear-elastic behaviour of FRP materials. Concrete members reinforced by hybrid FRP–steel bars can improve strength and ductility simultaneously. In this study, the plastic hinge problem of hybrid FRP–steel reinforced concrete beams was numerically assessed through finite element analysis (FEA). Firstly, a finite element model was proposed to validate the numerical method by comparing the simulation results with the test results. Then, three plastic hinge regions—the rebar yielding zone, concrete crushing zone, and curvature localisation zone—of the hybrid reinforced concrete beams were analysed in detail. Finally, the effects of the main parameters, including the beam aspect ratio, concrete grade, steel yield strength, steel reinforcement ratio, steel hardening modulus, and FRP elastic modulus on the lengths of the three plastic zones, were systematically evaluated through parametric studies. It is determined that the hybrid reinforcement ratio exerts a significant effect on the plastic hinge lengths. The larger the hybrid reinforcement ratio, the larger is the extent of the rebar yielding zone and curvature localisation zone. It is also determined that the beam aspect ratio, concrete compressive strength, and steel hardening ratio exert significant positive effects on the length of the rebar yielding zone.

Download Full-text

Laboratory Fast Corrosion Test of Plain Steel Bars in Concrete Beams

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.535-537.1803 ◽

2012 ◽

Vol 535-537 ◽

pp. 1803-1806

Author(s):

Shun Bo Zhao ◽

Peng Bing Hou ◽

Fu Lai Qu

Keyword(s):

Reinforced Concrete ◽

Concrete Beams ◽

Numerical Models ◽

Concrete Strength ◽

Reinforced Concrete Beams ◽

Uniform Corrosion ◽

Pure Bending ◽

Accelerated Corrosion ◽

Steel Bars ◽

Bending Length

An experimental study was carried out to examine the non-uniform corrosion of plain steel bars in reinforced concrete beams partially placed in 5% sodium chloride solution under conditions of accelerated corrosion. 4 reinforced concrete beams with different concrete strength were made. The crack distributions of the beams due to pre-loads and expansion of corrosion product, and the sectional corrosion characteristics of plain steel bars are described in detail. The sectional area loss relating to mass loss and change along pure bending length of the beams are discussed. These can be used as the basis of test for further studies to build the numerical models of serviceability of corroded reinforced concrete beams.

Download Full-text

Study of the reinforcement of structure members by polypropylene fibres waste

MATEC Web of Conferences ◽

10.1051/matecconf/201814901022 ◽

2018 ◽

Vol 149 ◽

pp. 01022 ◽

Cited By ~ 1

Author(s):

Khadra Bendjillali ◽

Mohamed Chemrouk

Keyword(s):

Reinforced Concrete ◽

Significant Contribution ◽

Concrete Beams ◽

Average Diameter ◽

Concrete Surface ◽

Point Of View ◽

Reinforced Concrete Beams ◽

Polypropylene Fibres ◽

Steel Bars ◽

Material Durability

The valorisation of industrial waste in the field of construction became a very interesting axis of research from scientific, economic and environmental point of view. We have conducted this work to study the effect of the addition of polypropylene fibres waste on the mechanical behaviour of reinforced concrete beams subjected to a simple flexural loading, with and without transversal reinforcement. The used fibres are coming from the waste of the fabrication of domestic brushes and sweeps; they have an average diameter of 0.47 mm and a length between 40 and 60 mm. Two weight dosages of fibres are used, 0.25 and 0.5 %. The experimental results showed that the incorporation of polypropylene fibres waste into the concrete affects negatively its workability, but its flexural and compressive strength are improved. The fibers have presented a significant contribution on the shear behavior and the cracking of beams, particularly in absence of transversal bars. The waste used in this work as fibrous reinforcement has not only increased the ductility of reinforced concrete beams, but it have also provided a perfect cracking distribution on the concrete surface and it has participated in a considerable way in the reduction of cracks number and dimensions, which allows to ensure the material durability and then the structure longevity. The reinforcement of concrete beams with 0.5 % of polypropylene fibers waste with a minimal steel bars can ensure an excellent mechanical behavior in shear, as in flexion.

Download Full-text